In this situation, the 2nd document, opens with the top bar hidden. [see image below]
there’s also some blank space at the top of the screen.
that hidden top bar, is available when pointing to the top screen edge.
there’s an easy workaround to help it into a normal full screen rhino document: Clicking the green traffic-light to once to take it out of full screen, and again to bring it back, and it comes back in correct form into full screen,
thanks a lot